In the present industrial society, an enormous amount of waste heat, which corresponds to 60% or more of the total amount of supplied primary energy, is exhausted to the natural environment mainly from factories, power plants, ironworks, automobiles, buildings, illuminators, ships, and so on. It is estimated that 75% or more of the waste heat is exhausted in the forms of hot water and gas that have a temperature of 250° C. or less. Thermoelectric power generation refers to generating power from such wasted and discharged heat. The thermoelectric power generation is therefore highly useful for protecting the Earth's environment. The waste heat is generally transferred through exhaust heat pipes such as cylindrical exhaust pipes and cylindrical wastewater pipes. In order to utilize the waste heat simply and efficiently as a heat source for the thermoelectric power generation, a thermoelectric conversion module needs to be flexible so as to be capable of being in contact with a curved outer surface of an exhaust heat pipe. Heat sources for the thermoelectric power generation have low temperature, and resultant temperature differential is small. This makes power generation efficiency low. Therefore, a module has to have low internal resistance in order to function as a power generation module. Thus, a module needs to include a large number of low-resistance thermoelectric elements mounted in an area as small as possible, and to be manufacturable at a low cost with good mass productivity. Further, in order to provide the thermoelectric elements with a largest possible temperature differential, a mounting substrate and other components of the module need to have low thermal resistance, and the module needs to have low contact thermal resistance when mounted to a pipe. Japanese Patent No. 5228160 discloses an example of known flexible thermoelectric conversion modules.